Re: [Discuss-gnuradio] Gnuradio/Beagleboard modifying flow graph buffer allocation

[Eric Blossom]

On Thu, Jun 10, 2010 at 07:07:35PM -0400, address@hidden wrote:

> hi, I'm working on Gnuradio on the Beagleboard.  I've managed to
> successfully integrate the DSP as a custom signal processing block
> and I'm essentially using TI library based buffers to transimt data
> between the GPP and DSP.  I'm trying to use pointers to copy data to
> and from the DSP instead of doing direct memory copies as per Philip
> Ballisters suggestion.  I'm familiar enough with the TI tool set to
> do that but I'm not very familiar with GNU Radio's base architecture
> to do the necessary changes and I was wondering if someone can help.
> 
> I basically need to allocate the data buffer through the TI toolset
> API instead of the vector class in C++, is there a good way to
> overide the buffer allocation in GNU Radio without "breaking" the
> flowgraph?  thanks.

If you are trying to do an alternate allocation method for the buffers
that are passed to the work methods, that's a _substantial_ amount of
work in the GNU Radio runtime.

It's possible, but would require a deep understanding of the guts of
GNU Radio, and then would require a fine piece of design to come up
with something that accomplishes this without breaking anything or
touching a lot of code in the runtime.

Start your exploration in gnuradio-core/src/lib/runtime :-)

See in particular gr_buffer.{h,cc}, and all the code that calls it.

Before you even go there, what percentage of CPU cycles and/or memory
bandwidth is being consumed by the copying when running a "typical"
application?  (Measure twice, cut once, time be time...)

> al fayez

Eric